The invention relates to a fitting for an opening roller of an open-end spinning device. The opening roller has several rows of teeth, extending essentially in circumferential direction of the opening roller, each of the teeth rows being separated by a groove which has a groove base, the lateral flanks of the teeth having a structured or textured surface and extending into the lateral flanks of the neighboring row.
In the case of a fitting of this kind (Germany Patent Document DE 40 38 352 A1), the lateral flanks of the teeth are provided with a patterning produced by means of surface tooling and resulting in a surface structure. The aim is, by means of this patterning, to create a surface which allows a good taking-along effect of the fibers, without however the fibers being affected to such a degree that dust particles are scraped off. The construction of the fitting and in particular the shape of the teeth has a considerable influence on the spinning result. The opening roller serves to separate fed-in fiber material, in the form of a sliver, into single fibers, which are then fed into a spinning element. The sliver is fed in at the relatively low speed of about one meter per minute, while the teeth of the fitting move at a considerably higher speed of, for example, 30 meters per second. The teeth of the fitting therefore penetrate at a very high speed into the sliver end, the so-called fiber beard, whereby they comb the fiber beard out and in this way separate out the single fibers.
An object of the invention is to make a fitting which gives an even better spinning result.
This object is achieved according to the invention in that the groove base is also provided with a structured surface.
The invention is based on the knowledge that some of the fibers are not only transported through the lateral flanks of the teeth, but on the groove base of the opening roller. If the fibers rest perfectly flat in contact with the surface of the groove base, this impedes the removal of fibers from the opening roller and their feeding into the spinning element. If, however, the groove base is provided also with a structured or textured surface, then the fibers there cannot rest flat, so that they can be drawn away by the suction air stream effecting the fiber transport and in this way they come away easier from the groove base.
In a further development of the invention it is provided that the teeth tips connecting the lateral flanks will not have a structured surface. The protection of the teeth tips by means of treatment of the teeth is known from German Patent Document DE 33 32 804 A1.
In relation to the mass of the teeth, the teeth tips have a very large surface area. If the teeth tips were not excluded from the structured surface area, they would, with the application of a structured surface receive the highest effect, which would be disadvantageous. A structured surface on the groove base, however, does not significantly alter the basic character of the fitting.
In the production of the preferred embodiments of the inventive fitting the structured surface is optimally applied to the fitting where it is only really necessary. The teeth tips should not be provided with the structured surface, so that they are not greatly affected and so do not become uneven.
The structured surface can be brought about chemically or mechanically by means of the use of a corroding substance, whereby the teeth tips are protected. This can be done in that the teeth tips are impregnated with a suitable substance. For example, the fitting can be treated in a shallow bath, whereby the teeth tips are simply wetted with an impregnating substance. In so far as embodiments of fittings with a ring mounting are concerned, it is contemplated to thread the ring mounting onto a shaft and to wet it by means of a transmitter roller. The ring mounting and the transmitter roller can then both rotate.
A small tank containing the impregnating substance can be attached to the transmitter roller. It is also an advantage for the transmitter roller to have a fitting which is suitable for taking up the impregnating substance and depositing it on the teeth tips. A brush with short bristles or alternatively, a textile coating which is absorbent enough, is suitable for this. The impregnating of the teeth tips can also be achieved by means of a suitable paste or powder.
In further new developments of the invention a coating is placed on the structured surface. Although in some cases an uncoated fitting is sufficient for the technical spinning requirements, it is advantageous to coat the fitting with, for example, the usual nickel-diamond coating, in particular when spinning fiber material which contains a synthetic mixture. It is sufficient when the structuring is only partially maintained, that is, it does not matter if the original structuring becomes burnished while being coated.
When, however, a specific amount of the structuring should remain intact, then the original structuring can be accentuated so that after treatment enough of the structure remains intact to be effective.
The structure is advantageous in that it consists of notches and waves. It is therefore not so important to make the structured surface particularly even.
Expediently the groove base opposite the lateral flanks of the teeth is deepened. Through this process the grooves in the area of the groove base are provided with a continuous small wall on the sides, which is advantageous for the guiding of the fibers.
In a particularly advantageous new development of the invention the fitting is formed from a base body by means of a cutting process. This has the advantage that, in contrast to the standard saw-tooth wires, the teeth, in their teeth form, can be better adapted to the technical spinning requirements.
Expediently the groove base may have an almost semi-circular cross-section. With this configuration the loose fibers can be removed more easily from the fitting.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.